The total interval number of an n-vertex graph with maximum degree β is at most (β+1/β)n/2, with equality if and only if every component of the graph is K β,β . If the graph is also required to be connected, then the maximum is βn/2 + 1 when β is even, but when β is odd it exceeds [β + 1/(2.5β + 7.7
Generalized degree conditions for graphs with bounded independence number
β Scribed by Ralph Faudree; Ronald J. Gould; Linda Lesniak; Terri Lindquester
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 511 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0364-9024
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β¦ Synopsis
We consider a generalized degree condition based on the cardinality of the neighborhood union of arbitrary sets of r vertices. We show that a Dirac-type bound on this degree in conjunction with a bound on the independence number of a graph is sufficient to imply certain hamiltonian properties in graphs. For K,,,,-free graphs we obtain generalizations of known results. In particular we show:
Theorem. Let r 2 1 and rn 2 3 be integers. Then for each nonnegative function f(r, rn) there exists a constant
(c) Gis hamiltonian-connected if 6(G) 2 r + ' 2 and Gis 3-connected.
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